The present invention relates to an image recording apparatus using a microcapsule carrying sheet and a separate developer sheet.
In a photocopying technique of this kind, the microcapsule carrying sheet includes a substrate and microcapsules coated thereon. Each of the microcapsules contains a chromogenic material (dye precursor or color former) and a phtosensitive material (photo-curable resin). On the other hand, the developer sheet includes a substate and developer material coated thereon. Upon light exposure, curing of the photosensitive material in the microcapsules occurs in light-exposed areas of the microcapsule layer. When the microcapsule layer and the developer material layer are in pressure contact with each other, the microcapsules at unexposed parts in remaining parts of the microcapsule layer are ruptured. As a result, the dye precursor flowed from the ruptured capsules is reacted with the developer material for forming an image on the developer sheet in conformance with an original image.
One conventional image recording apparatus is shown in FIG. 1. According to the apparatus, a weblike microcapsule carrying sheet 6 extends between a sheet cassette roll 5 and a take-up roller 7. A light source 1 is disposed above a trichromatic resolution filter 2, and a light transmittive member 3 on which a picture image is provided is disposed below the filter 2. A condensing lens 4 is disposed below the light transmittive member 3, and the microcapsule carryng sheet 6 brigding between the sheet cassette roll 5 and the take-up roller 7 confronts the condensing lens 4. A developer sheet cassette 8 in which developer sheets 9 are stacked is disposed above the capsule carrying web 6. A feed roller 10 is provided to successively feed the developer sheet over the weblike sheet 6. A pressure unit P such as a pair of pressure rollers 11 is provided at a position downstream of the confluent position of the sheet 6 and the sheet 9. Further, an image fixing unit H such as a pair of heat rollers 12 is disposed downstream of the pressure rollers 11.
Light emitted from the light source 1 passes through the trichromatic resolution filter 2, the light transmittive member 3 and the condensing lens 4, so that a microcapsule layer of the capsule carrying sheet 6 is irradiated. As a result, a latent image is formed on the capsule carrying sheet 6 in conformance with the picture image on the transmittive member 3. This latent image is formed upon photo-curing of the photo-curable resin in the microcapsules as shown by reference numeral 6a in FIG. 2(b) because of the light exposure. Upon completion of the light exposure, the sheet 6 is transferred in a direction A by the rotation of the take-up roller 7. During this sheet transfer, the feed roller 10 is operated to discharge the developer sheet 9 stacked on the sheet cassette 8, so that the developer material layer of the developer sheet 9 is overlapped with the microcapsule layer of the sheet 6 at the confluent position, and these sheets 6 and 9 pass through the pair of pressure rollers 11. As a result, remaining microcapsules whose photo-curable resins are maintained in their liquid state because of non light exposure are ruptured, and the dye precursor of the remaining microcapsules is reacted with the developer material of the developer sheet 9 for providing color image on the developer sheet 9 in conformance with the original image. The pair of heat rollers 12 is disposed allowing the developer sheet 9 to pass therethrough in order to perform image fixing. As a result, coloring quality is improved to enhance gloss level.
With this arrangement, during pressure contact between the microcapsule carrying sheet 6 and the developer sheet 9 at the pressure rollers 11, minute recesses 9a may be formed on the surface of the developer sheet 9 as shown in FIG. 2(b) at positions corresponding to the photo-cured portions 6a of the capsule carrying sheet 6 due to their rigidity. Therefore, glossy image may not be finally obtainable on the developer sheet 9 due to the surface irregularities, even if the sheet 9 passes through the heat rollers 11.